Automatic engine-governor.



W. SCHMIDT. AUTOMATIC ENGINE GOVERNOR. APPLICATION FILED 21613.25, 1914.

1,107,204, I l Patented Aug-.11,1914

A TTUR/VEVS UNITED STATES PATENT OFFICE.

WrLHELM SCHMIDT, OE cASSEL-WILHELMsHHE, GERMANY, AssrGNOE To SCHMIDTSCHE HEISSDAMPF GESELLSCHAFT M. B. H., or cAssEL-WIL- HELMSHHE, GERMANY, A CORPORATION 0E GERMANY.

AUTOMATIC ENGINE-GOVERNOR.

Specification of Letters Patent,

Pa-tented Aug. 11, 1914.

fnl Improvements in Automatic Engine- Governors, of which the following is aspeciiication.

My invention relates to engine governors for reciprocating engines and is especially adapted and intended for engines of the type shown in my German Patent Number 76,651 of September 4, 1894. In the engine there disclosed the steam Or driving medium is admitted by the aid of an inlet element which opens and closes automatically under the influence of pressure changes produced by the moving pistonwith which the inlet element is associated. The structure and operation here disclosed maybe said to be a. modification of and an improvement upon that disclosed in my application for United States patent for engine governors, Serial No. 666,275, filed December 1c, 1911.

It is the object of my invention to provide an engine governor of the type indicated in which the loss of steam or driving fluid consequent upon the operation of the governor Shall be very Small.

A further object of my invention is to provide a governor of the type indicated which shall be simple 1nd reliable.

Other Objects will appear as thefspeciication proceeds.

My invention will be better understood by referring to the drawings in which- Figure l represents a longitudinal section thror'fh one end of a cylinder and piston embodying a preferred form of the invention Figs. and 3 show respectively similar sections of two modifications of my invention. the cylinder and inlet valve features being omitted.

Referringr to Fig. l of the drawings the.

steam cylinder A is provided with a piston B, steam inlet C, and outlets D controlled b v said piston. In the cylinder end is a ring shaped inlet opening E controlled by a main or ringl valve c lying in the Steam inlet chamber f7. This inlet chamber is provided with a valve (relief) piston attached to and. forming part of the ring valve c, this piston being hollow and in free permanent communication at its bottom with the inlet chamber d. This piston f functions in a cylindrical guide way f from the wall of which the piston is slightly separated by a space g. At top and bottom of the guide way f there are provided upon said guide way, valve seats a and b, and rings a, b upon the piston, are arranged to engage respectively with said valve seats when the piston is down or up, So as in either case to shut off the passage formed 'by the space g between' the inlet chamber (Z and the relief chamber e. The relief chamber e has an outlet 7i at the top thereof going to the atmosphere O1' to a Suitable steam collector and controlled by a pressure regulator z', which may be either operated by hand or automatically. This controlled outlet is of the same general structure as is shown and described in my application SerialA Number 666,275 filed December 1G, 1911, previously referred to, and my present invention is not directly concerned therewith.

The operation of my invention is as follows: Fig. l shows the main piston B as it appears shortly before it reaches the end of its return (upward) stroke and after the exhaust is already shut off. The ring valve c is closed thus preventing live steam from passing into the cylinder through the inlet opening E, and t-he ring a is also closed against the upper valve seat a so as to prevent the passage of live steam from the inlet chamber to the relief chamber e. As soon as the exhaust is Shut off, compression takes place above the main piston B and, before this compression pressure becomes as great as that of the live steam in the inlet cham ber, ring valve c with valvel pist-on f rises and permits a small quantity of steam to pass through the passage g into the relief chamber c; this passage of steam is, however, immediately cut off by the closure of ring b against the lower valve scat 7J. The quantity of steam which enters the relief 'chamber is, therefore, quite small. lThe main piston now reaches the end of its stroke and begins to move forwardl)7 (downward) at increasing velocity under the pressure of live steam which enters through the ring shaped inlet opening E` the ring valve c being:I now open. The pressure in the main cylinder above the piston will decrease more or less rapidly, according to the speed of the Ipassage. g to the relief chamber.

piston, owing tothe throttling in the inlet opening, and when this pressure has fallen sufhciently low, the valve piston f vwill be pressed downwardly so as to cause the ring valve c to close the inlet opening and the ring a to set against the upper valve seat a. As the valve piston f is pushed downwardly live steam will again be admitted through Steam from the relief chamber will pass through the outlet h at a. speed depending upon the setting of the pressure regulator z'.

It will be noted that my automatic governor, as above described, operates by reason f of the steam lwhich is permitted to pass through the passage g, relief chamber e and the outlet L. This quantity of steam is, of course, wasted so far as effective work is concerned, but by my invention the waste 1s made extremely small since the steam can How through passage g actually only for the period during which the valve piston is in motion either up or down to seat one or the other of the rings a and b against the cor responding valve seats a and b. On account of this small interval of time during which the steam is actually flowing, it is possible to leave ample clearance space between relief valve and the guideway f so as to insure smooth and easy working of the valve at all times.

An advantage of my invention, as herein described, is that the pressure of the ring valve c upon its valve seat is relieved to a' considerable extent by the fact that ring a,

- simultaneously seats upon'the valve seat a.',

This enables the main valve seat of the ring' valve c to be kept narrow and obviates the disadvantages of broad seat surfaces.

The relier' chamber e is not essential to theV operation of my invention and the space above valve piston f may be entirely open' to the atmosphere within the spirit of my in-Q vention.

The ring b and valve seat b may be= omitted within the scope of the inventiveideal The passage g will then be closedf when the inlet opening E is closed and steami can only pass from the inlet chamber, through the. passage g, while inlet opening E is open.

My invention may be embodied in various modified forms within the spirit of the same and the claims. Thus Figs. 2 and 3 show modifications especially suitable for engines where high speed of rotation is used, the moving valve system being so designed as to have very small weight and inertia. In these modifications the relief piston or the main valve has a cup-like form. In Fig. 2 the valve piston moves in a cylindrical guideway 7c provided with a plurality of annular grooves whereby the contact surface between valve piston and guldeway 1s diminished. The clearance space Z between valve piston and guidewa-y 7c has preferably a radial thickness of anything between 0.02 and 0.05 mms. While the main valve t is open, steam passes through spaces Z into reliefchamber n and fills the same, and when the main valve is closed the steam contained in space n expands into the space 0 within the cup. As in the case of the form shown in Fig. l, steam can only pass into the relief chamber for the very short period during which the main valve is either opening or closing. The throttling due to the labyrinth of ,the guideway is, however, so great that practically almost no steam what ever passes during this short period.

In Fig. 8 the spaces between the two seat surfaces g and r fill with live steam through the clearance space w while the main valve .2: is open and this steam passes, when the' main valve is closed, into the relief chamber u where it expands to the pressure ot said chamber. The reliefvalve in this modification is guided in its movement upon the journal o which is provided with annular grooves having the same purpose as the grooves of the piston in Fig. 2 and the length of lift is limited as before by the seat '1'.

Besides the modifications shown in Figs.V 2 and 3 other forms can readily be used within the inventive idea.

The essential feature of the invention resides in the interruption of the flow of driving means from the inlet chamber to relief chamber, either while the main valve is closed only, or both while the valve is closed and while it is fully open.I

The means by which the valves are automatically opened and closed is immaterial so far as the resent invention is concerned, it being mere y suiiicient to know that during each to and fro movement of the main piston, the valves are once opened and once closed.

vHaving described my invention I claim:

l. The combination, with an engine cylinder provided with a piston, an inlet chamber at the end of' said cylinder and an inlet opening from said inlet chamber into said cylinder, of controlling means for said inlet opening comprising a main valve, means for leading steam from the inlet chamber to both sides of said main valve, and means for shutting off the steam flow through said last named means when the main valve is closed.

2. The combination, with an engine cylinder provided with a piston, an inlet chamber at the end of said cylinder and an inlet opening from'said inlet chamber into said cylinder, of controlling means for said inlet opening comprising a main valve, a passage for leading steam from the inlet chamber to both sides of said main valve, and an auxiliary valve for shutting off the steam opening comprising a relief piston, a relief space into which the relief piston extends Which space is normallymt lower pressure than the inlet chamber, a passage connecting the inlet chamber and the relief space, and a valve attached to said relief piston for closing said passage when the main valve is closed.

6. The combination, with an engine cylinder provided With a iston, an inlet chamber at the end of saidp cylinder and an inlet opening from said inletchamber into said cylinder, of a main valve for said inlet opening comprising a. relief piston, a relief space into which the relief piston extends which spa-ce is normally at lower pressure than the inlet chamber, a passage connecting vthe inlet chamber and the relief space, a valve attached to said relief piston for closing said passage When the main valve is flow through said passage when the main valve 1s closed.

inder provided with a piston, an inlet chamber at the end of said cylinder and an inlet..4 opening from said inlet chamber into said cylinder, of controlling means for said inlet opening comprising a main valve having a relief piston, a passage between the inlet chamber and the outer side of the relief piston, and an auxiliary valve controlled by said relief piston for shutting olf the steam How through said passage when the main valve is closed.

4. The combination, with an engine cylinder provided with a piston, an inlet chamopening from said inlet chamber into said cylinder, of a main valve for said inlet opening comprisinof a relief pist-on part of Which lies outside the inlet cham r, a passage leading from said inlet chamber to said outlying portion of the relief valve, and means controlled by the relief Valve for closing said passage When the main valve is closed.

5. The combination, with an engine cylinder provided with a piston, an inlet chamber at the end of said cylinder and an inlet opening from said inlet chamber into said cylinder, of a main valve for said inlet When the main valve is open.

In testimony whereof I have hereunto set my hand in the presence of tivo subscribing Witnesses.

WILHELM SCHMIDT.

Witnesses:

EGMoNT DoLTTLorF, AUGUST G. R-Uon. 

